Air conditioner

ABSTRACT

To obtain an air conditioning apparatus which provides a favorable atmosphere to the ear and saves energy even if the suction resistance of the impeller becomes high due to such as dust in the air conditioning apparatus. The air conditioning apparatus is provided with an impeller which is formed by a plurality of vanes and a ring for supporting the plurality of vanes, and includes a nozzle portion formed by a stabilizer and an air outlet, a cross flow fan formed by a guide wall, and a heat exchanger. The ratio H/φD 2  of the outside diameter φ D 2  of the impeller to the height H of the air conditioning apparatus is 2.2 or above and 3.0 or below.

TECHNICAL FIELD

The present invention relates to an air conditioning apparatus such asan air conditioner, a dehumidifier and an air purifier, and moreparticularly to an air conditioning apparatus in which a cross flow fanis mounted to be used as a blowing means.

BACKGROUND ART

Hereafter, a description will be made of an air conditioning apparatus,such as an air conditioner, a dehumidifier and an air purifier, in whicha conventional cross flow fan is mounted. An example of the conventionalcross flow fan entitled “Indoor Unit for Air Conditioner” is disclosedin Japanese Unexamined Patent Publication No. Hei 11-83062, forinstance. FIG. 50 is a longitudinal cross-sectional view of the mainbody of an air conditioning apparatus disclosed in Japanese UnexaminedPatent Publication No. Hei 11-83062. FIG. 51 is a perspective view ofthe impeller of a conventional cross flow fan. FIG. 52 is a longitudinalcross-sectional view of the cross flow fan of FIG. 51. FIG. 53 is across-sectional view of a vane shown in FIG. 52. FIG. 54 is a diagramillustrating the frequency characteristic of noise of the airconditioning apparatus in which the conventional cross flow fan ismounted.

With referring to FIGS. 50, 51 and 52, the conventional cross flow fanis formed by an impeller 101, a guide wall 102, a stabilizer 103, and amotor 104. The impeller 101 is formed by two or more units 110 a whichare connected in the direction of the shaft, each unit being formed by aplurality of vanes 101 b and a ring 101 c for supporting the pluralityof vanes. The guide wall 102 surrounds the impeller 101 in such a manneras to cover one side of the peripheral surface of the impeller 101. Thestabilizer 103 is disposed in such a manner as to face the guide wall102. The motor 104 rotates and operates the impeller 101 as indicated byan arrow J.

According to the air conditioning apparatus in which the thus configuredconventional cross flow fan is mounted, as shown in FIG. 50, air issucked in through a detachable front facing grill and a detachable topfacing inlet grill, then dust is removed from the air by using a filter,and thereafter the air is heated or refrigerated by means of a heatexchanger which is formed in such a manner as to surround the impeller101. Heat-exchanged air after passing through the heat exchanger issucked into the impeller 101, passes through a row of vanes on the sideof the heat exchanger, and then is blown off again through a row ofvanes on the side of an air outlet. Then, the air is blown off throughthe air outlet to the room by blowing-direction changing vanes,including up/down vanes and left/right vanes, changing the blowingdirection of the air. Thus, the room is air-conditioned.

With referring now to the vane 101 b in a cross-sectional shape shown inFIG. 53, a reference numeral A20 denotes a tip of a vane's peripheralend portion A2 in the shape of a circular arc of the vane 101 b. Areference numeral A10 denotes a tip of a vane's internal circumferentialend portion A1 in the shape of a circular arc of the vane 101 b. Areference mark O denotes the center of the rotating shaft of theimpeller 101, and a reference numeral 1 denotes the center of a camberline P0 formed into a single circular arc of the vane 101 b. A referencenumeral P2 denotes a pressure face of the vane 101 b on a side facingthe direction of rotation of the impeller, and a reference numeral P3denotes a suction surface opposing to the pressure face P2. O-A20indicates a first straight line connecting the tip of the vane'speripheral end portion A20 of the vane 101 b and the center O. O1-A20indicates a second straight line connecting the tip of the vane'speripheral end portion A20 of the vane 101 b and the center O1 of thecamber line P0. Further, a reference mark n denotes a firstperpendicular of the first straight line O-A20 to the tip of the vane'speripheral end portion A20, and a reference mark m denotes a secondperpendicular of the second straight line O1-A20 to the tip of thevane's peripheral end portion A20. An exit angle β2 is an acute angleformed by the first perpendicular and the second perpendicular.

With referring to the cross flow fan, for example, by expanding theoutside diameter φD2 of the impeller 101 in a similar shape, the flowrate is increased and the noise level is lowered. However, if the flowrate is increased and the noise level is lowered in such a manner,singular noise S1 is generated in a low frequency range as shown in thediagram illustrating the frequency characteristic of noise of FIG. 54.In addition to that, there may be a case where the noise level at thesame flow rate is increased and a resultant atmosphere to the ear ismade worse. For that reason, according to the conventional cross flowfan, the singular noise S1 is tried to be reduced by setting the exitangle β2 of the vane 101 b to 23 degrees or less. Furthermore, bysetting the exit angle β2 to 18 degrees or more, the noise level at thesame flow rate is lowered and a resultant atmosphere to the ear iscontrolled not to be aggravated.

Furthermore, by forming the vane 101 b such thatt_(max)/t_(min =)1.3˜1.5, a blowing performance at a high flow rate maybe obtained, where t_(max) denotes a maximum thickness of the vane 101 band t_(min) denotes the thickness of the vane's peripheral end portion,which is the thickness of a portion of the vane 101 excluding a roundishportion at a mounting end of the vane 101 on the vane's peripheral side.In addition to that, this also allows to obtain an interior unit of anair conditioner which has less opportunities of generating the singularnoise in a low frequency range.

However, according to an air conditioning apparatus using theconventional cross flow fan disclosed in Japanese Unexamined PatentPublication No. Heill-83062, in the case that the suction resistance ofthe impeller 101 becomes high due to a decrease in the fin pitch of theheat exchanger, or dust accumulated on the filter, a circulating vortexC1 caused near the stabilizer 103, which is a typical phenomenon of across flow fan, may develop from a solid circle to a broken bold circle.Then, air after passing through the heat exchanger flows towards a crossflow vortex having a lower pressure, and then sucked into the impeller101 as indicated by the arrow of FIG. 50. As a result, in an area F1,the flow of air may be detached from the vane 101 b, and then an airturbulent vortex G1 may be generated at a rear portion of the vane 101b. Consequently, as shown in the diagram illustrating the frequencycharacteristic of noise of FIG. 54, there may be a case where thesingular noise Sm having a frequency width fs is generated in a lowfrequency range of around 40 to 80 percent of the generation frequencyof the rotation noise (NZ sound) depending upon the number of vanes Zand the rotational frequency N [r.p.m] of the impeller 101. For thatreason, a jarring noise other than the rotational noise may begenerated, which produces an aggravated atmosphere to the ear, and thishas been a problem.

Furthermore, because the vane's exit angle β2 is reduced, therebynarrowing a vane's distance, when the flow of air passes between vanes,a resistance occurs. As a result, the shaft output for operating theimpeller is increased, which increases the power consumption of themotor.

Hence, the present invention has been devised to solve the abovedescribed problems, and an object is to obtain an air conditioningapparatus which provides a favorable atmosphere to the ear and savesenergy by controlling noise not to be aggravated even if the suctionresistance of the impeller becomes high due to such as noise and dustduring its operation, and further, by minimizing the generation of thesingular noise in a low frequency range and the rotation noise, andminimizing the power consumption of the motor.

DISCLOSURE OF THE INVENTION

An air conditioning apparatus according to a first invention ischaracterized by having a cross flow fan which includes an impellerbeing formed by a plurality of vanes and a ring for supporting theplurality of vanes, and a heat exchanger. Then, the cross flow fanincludes a nozzle portion which is formed by a stabilizer and an outlet,and a guide wall. A ratio H/φD2 of a height H of a main body of the airconditioning apparatus to an outside diameter φD2 of the impeller is 2.2or above and 3.0 or below.

An air conditioning apparatus according to a second invention ischaracterized by an impeller of a cross flow fan in which a vane's exitangle β2 is between 23 degrees and 30 degrees.

An air conditioning apparatus according to a third invention ischaracterized by an impeller of a cross flow fan in which a ratio tm/t2of a maximum thickness tm of the vane of the impeller of the cross flowfan to a minimum thickness t2 of the vane is at least 1.5 or above and3.5 or below when the minimum thickness t2 is a diameter of a peripheralend portion of the vane in a shape of a circular arc so as to reducesingular noise generated in a frequency range lower than that ofrotation noise, and a thickness of the vane is gradually varied.

An air conditioning apparatus according to a fourth invention ischaracterized by an impeller of a cross flow fan in which a maximumthickness of a vane of the impeller of the cross flow fan is between 0.9mm and 1.5 mm when a minimum thickness t2 of the vane of the impeller ofthe cross flow fan is between 0.2 mm and 0.6 mm and the minimumthickness t2 of the vane is a diameter of a peripheral end portion ofthe vane in a shape of a circular arc.

An air conditioning apparatus according to a fifth invention ischaracterized by an impeller of a cross flow fan in which the maximumthickness of the vane of the impeller of the cross flow fan is between0.9 mm and 1.5 mm when the minimum thickness t2 of the vane of theimpeller of the cross flow fan is between 0.2 mm and 0.6 mm and theminimum thickness t2 is the diameter of the peripheral end portion ofthe vane in the shape of the circular arc.

An air conditioning apparatus according to a sixth invention ischaracterized by an impeller of a cross flow fan in which the vane isformed into a shape of an edge obtained by cutting the vane along acircle passing through a peripheral end portion of the vane where acenter of the circle is a center O of a rotating shaft of the impeller.

An air conditioning apparatus according to a seventh invention ischaracterized by an impeller of a cross flow fan in which the vane isformed into a shape of an edge obtained by cutting the vane along acircle passing through the peripheral end portion of the vane where acenter of the circle is a center O of a rotating shaft of the impeller.

An air conditioning apparatus according to an eighth invention ischaracterized by an impeller of a cross flow fan in which the pluralityof vanes is fitted with an irregular space between the vanes in pitch.

An air conditioning apparatus according to a ninth invention ischaracterized by an impeller of a cross flow fan in which the pluralityof vanes of the impeller of the cross flow fan is fitted with anirregular space between the vanes in pitch.

An air conditioning apparatus according to a tenth invention ischaracterized by a cross flow fan in which the stabilizer is formed at alower front portion of the air conditioning apparatus in such a mannerthat an acute angle formed by a straight line, and a horizontal line isbetween 30 degrees and 70 degrees when the straight line connects aclosest point of the stabilizer to the impeller of the cross flow fan toa center O of a rotating shaft of the impeller and a horizontal line andthe horizontal line passes through the center O of the rotating shaft ofthe impeller.

An air conditioning apparatus according to an eleventh invention ischaracterized by the stabilizer which is formed in such a manner that anacute angle formed by two straight lines is between 15 degrees and 40degrees when the two straight lines connect a center O of the impellerof the cross flow fan, respectively, to a closest point of thestabilizer to the impeller of the cross flow fan and to a lower portionof the stabilizer.

An air conditioning apparatus according to a twelfth invention ischaracterized by a cross flow fan in which the guide wall is formed atan upper rear portion of the air conditioning apparatus in such a mannerthat an angle θ3 formed by a straight line and a horizontal line isbetween 35 degrees and 80 degrees when the straight line connects aclosest point of the guide wall to the impeller of the cross flow fanand a center of a rotating shaft of the impeller and the horizontal linepasses through the center O of the rotating shaft of the impeller,

An air conditioning apparatus according to a thirteenth invention ischaracterized by an impeller of a cross flow fan in which a shape of aperipheral end portion of the vane extends to a peripheral side of theimpeller in a shape of an inclining parallelogram forward in a directionof rotation of the impeller, but the shape is not projecting outside aperiphery of the ring for supporting the plurality of vanes, in across-sectional view at right angles to a line of a rotating shaft ofthe impeller of the cross flow fan.

An air conditioning apparatus according to a fourteenth invention ischaracterized by an impeller of a cross flow fan in which two vertexesof a peripheral end portion of the vane facing a peripheral side of theimpeller are formed in a fixed shape of R when the vertexes extend tothe peripheral side of the impeller in a shape of parallelogram.

An air conditioning apparatus according to a fifteenth invention ischaracterized by an impeller of a cross flow fan in which each of theplurality of vanes of the impeller of the cross flow fan is inclined bya fixed angle to a rotating shaft of the cross flow fan.

An air conditioning apparatus according to a sixteenth invention ischaracterized by an impeller of a cross flow fan in which a peripheralend portion of the vane of the impeller of the cross flow fan is formedby an elastic body.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an external view illustrating the structure of an airconditioning apparatus according to a first embodiment of the presentinvention.

FIG. 2 is a partial cross-sectional view of the air conditioningapparatus of FIG. 1.

FIG. 3 is a longitudinal cross-sectional view of the air conditioningapparatus of FIG. 1.

FIG. 4 is a perspective view of a cross flow fan in FIG. 1.

FIG. 5 is a longitudinal cross-sectional view of the cross flow fan ofFIG. 4.

FIG. 6 is a diagram illustrating the relationship between a ratio H/φD2of the outside diameter φD2 of an impeller to the height H of the mainbody and the noise level SPL[dBA] at the same flow rate Q[m³/min].

FIG. 7 is a diagram illustrating the relationship between the ratioH/φD2 and a maximum level of singular noise Sw[dBA].

FIG. 8 is a diagram illustrating a shape of a vane 2 b of the impellerof a cross flow fan to be used as an air blowing means for an airconditioning apparatus of a second embodiment of the present invention.

FIG. 9 is a diagram illustrating a state of a vane's peripheral endportion A2 of the vane 2 b of the impeller 2 according to the airconditioning apparatus of this invention in a case where an exit angle 2is too large.

FIG. 10 is a diagram illustrating the relationship between the vane'sexit angle β2 and the motor power consumption Wm[W] according to the airconditioning apparatus of this invention.

FIG. 11 is a diagram illustrating a shape of a vane 2 b of the impellerof a cross flow fan to be used as an air blowing means for an airconditioning apparatus of a third embodiment of the present invention.

FIG. 12 is a diagram illustrating changes in the level of the singularnoise Sm when a thickness ratio tm/t2 is varied in the cases of a filter12 with and without dust being accumulated.

FIG. 13 is a diagram illustrating changes in the noise level SPL[dBA] atthe same flow rate in the cases of the filter 12 with and without dustbeing accumulated.

FIG. 14 is a diagram illustrating a shape of a vane 2 b of the impellerof a cross flow fan to be used as an air blowing means for an airconditioning apparatus of a fourth embodiment of the present invention.

FIG. 15 is a diagram illustrating a state of the suction flow of air atthe vane's peripheral end portion A2 of a conventional impelleraccording to the air conditioning apparatus of this invention.

FIG. 16 is a diagram illustrating a change in the power consumption of afan motor 5 when a vane's minimum thickness is varied according to theair conditioning apparatus of this invention.

FIG. 17 is a diagram illustrating a state in which minute pieces ofdust, being left unremoved through a filter, are accumulated on the tipA20 of the vane's peripheral end portion of the impeller 2 according tothe air conditioning apparatus of this invention.

FIG. 18 is a diagram illustrating the operating time and the air flowdrop rate at the same rotational frequency of each case of theconventional cross flow fan and the cross flow fan of the airconditioning apparatus of this invention.

FIG. 19 is a diagram illustrating a basic form of the shape of a vane 2b of the impeller 2 of a cross flow fan to be used as an air blowingmeans for an air conditioning apparatus of a fifth embodiment of thepresent invention.

FIG. 20 is an enlarged view of a tip A20 of the vane's peripheral endportion obtained by changing the basic form of the shape of the tip A20of the vane's peripheral end portion of FIG. 19.

FIG. 21 is a diagram illustrating a state of air flow at thecircular-arc shaped vane's peripheral end portion A20 of a conventionalvane 2 b according to the air conditioning apparatus of this invention.

FIG. 22 is a diagram illustrating the power consumption Wm[W] of the fanmotor 5 for operating an impeller of a cross flow fan in each case ofthe conventional cross flow fan and the cross flow fan of the airconditioning apparatus of this invention in comparison.

FIG. 23 is a longitudinal cross-sectional view of an impeller 2 of across flow fan to be used as an air blowing means for an airconditioning apparatus of a sixth embodiment of the present invention.

FIG. 24 is a diagram illustrating the frequency characteristic of noiseof an air conditioning apparatus in which a conventional cross flow fanis mounted according to the air conditioning apparatus of thisinvention.

FIG. 25 is a diagram illustrating the frequency characteristic of noiseof the air conditioning apparatus in which the cross flow fan of thisinvention is mounted.

FIG. 26 is a diagram illustrating a state in which a trailing vortex G2of a pipe 13 a is directly sucked into the impeller 2, when pipes 13 bof a heat exchanger 13 are close to the impeller 2, according to the airconditioning apparatus of this invention.

FIG. 27 is a diagram illustrating the relationship in the powerconsumption of the fan motor for operating a cross flow fan at the sameflow rate between the conventional cross flow fan and the inventivecross flow fan according to the air conditioning apparatus of thisinvention.

FIG. 28 is a longitudinal cross-sectional view of an air conditioningapparatus according to a seventh embodiment of the present invention.

FIG. 29 is a schematic diagram of the air conditioning apparatus of thisinvention illustrating a case where an acute angle θ1 is more than 70degrees, the acute angle θ1 being formed by a straight line 0-3 a ₁,which connects a closest point 3 a ₁ of a stabilizer to the impeller ofthe cross flow fan to the center 0 of the rotating shaft of theimpeller, and a horizontal line L0, which passes through the center 0 ofthe rotating shaft of the impeller.

FIG. 30 is a diagram illustrating the frequency characteristic of noiseof an air conditioning apparatus in which the conventional cross flowfan is mounted according to this invention.

FIG. 31 is a diagram illustrating a change in the singular noise levelSw when the acute angle θ1 is varied according to the air conditioningapparatus of this invention.

FIG. 32 is a schematic diagram of the air conditioning apparatus of thisinvention illustrating a case where the acute angle θ1 is small.

FIG. 33 is a diagram illustrating the relationship between the acuteangle θ1 and the noise level, the acute angle θ1 being formed by thestraight line 0-3 a ₁ which connects the closest point 3 a ₁ of thestabilizer to the impeller of the cross flow fan to the center 0 of therotation shaft of the impeller and the horizontal line L which passesthrough the center 0 of the rotating shaft of the impeller.

FIG. 34 is a longitudinal cross-sectional view of an air conditioningapparatus according to an eighth embodiment of the present invention.

FIG. 35 is a diagram illustrating the relationship between an acuteangle θ2 and the noise level, the acute angle θ2 being formed by twostraight lines 0-3 a ₁ and 0-3 a ₂ connecting a closest point 3 a ₁ of astabilizer 3 a to an impeller and a lower portion 3 a ₂ of thestabilizer, respectively, according to the air conditioning apparatus ofthis invention.

FIG. 36 is a diagram illustrating the relationship between the acuteangle θ2 and the power consumption Wm[W] of the fan motor according tothe air conditioning apparatus of this invention.

FIG. 37 is a longitudinal cross-sectional view of an air conditioningapparatus according to a ninth embodiment of the present invention.

FIG. 38 is a schematic diagram of the air conditioning apparatus of thisinvention illustrating a case where an angle θ3 is small, the angle θ3being formed by a straight line 0-3 b ₁ and a horizontal line L0, thestraight line 0-3 b ₁ connecting a closest point 3 b ₁ of a guide wall 3b to the impeller to the center 0 of the rotating shaft of the impellerand the horizontal line L0 passing through the center 0 of the rotatingshaft of the impeller.

FIG. 39 is a schematic diagram of the air conditioning apparatus of thisinvention illustrating a case where the angle θ3 is large.

FIG. 40 is a diagram illustrating a change in the noise level at thesame flow rate when the angle θ3 is varied, in a case where the closestpoint 3 b ₁ of the guide wall 3 b to the impeller 2 of the cross flowfan is disposed in an upper rear portion of the air conditioningapparatus, and the angle θ3 is formed by the straight line 0-3 b ₁,connecting the closest point 3 b ₁ of a guide wall 3 b to the impellerto the center 0 of the rotating shaft of the impeller, and thehorizontal line L0 passing through the center 0 of the rotating shaft ofthe impeller.

FIG. 41 is a diagram illustrating a change in the power consumption ofthe fan motor at the same flow rate when the angle θ3 is variedaccording to the air conditioning apparatus of this invention.

FIG. 42 is a partial cross-sectional view of a vane of the impeller of across flow fan to be mounted in an air conditioning apparatus accordingto a tenth embodiment of the present invention.

FIG. 43 is an enlarged view of an area in the vicinity of the vane'speripheral end portion of FIG. 42.

FIG. 44 is a diagram illustrating the flow of air between the vanes wheneach vane is formed into the shape of this invention.

FIG. 45 is an enlarged view of an area in the vicinity of the vane'speripheral end portion of the impeller of a cross flow fan to be mountedin an air conditioning apparatus according to an eleventh embodiment ofthe present invention.

FIG. 46 is a perspective view of the impeller of a cross flow fan to bemounted in an air conditioning apparatus according to a twelfthembodiment of the present invention.

FIG. 47 is a diagram illustrating the frequency characteristic of an airconditioning apparatus in which the impeller of the conventional crossflow fan is mounted.

FIG. 48 is a diagram illustrating the frequency characteristic of theair conditioning apparatus in which the impeller of the cross flow fanof this embodiment is mounted.

FIG. 49 is a partial cross-sectional view of the impeller of a crossflow fan to be mounted in an air conditioning apparatus according to athirteenth embodiment of the present invention.

FIG. 50 is a longitudinal cross-sectional view of a conventional airconditioning apparatus.

FIG. 51 is a perspective view of the impeller of the cross flow fan ofthe conventional air conditioning apparatus.

FIG. 52 is a longitudinal cross-sectional view of the cross flow fan ofthe conventional air conditioning apparatus.

FIG. 53 is a cross-sectional view of a vane of the cross flow fan of theconventional air conditioning apparatus.

FIG. 54 is a diagram illustrating the frequency characteristic of noiseof the air conditioning apparatus in which the conventional cross flowfan is mounted.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereafter, descriptions will be made in detail of the embodiments of theair conditioning apparatus of the present invention with reference tothe drawings.

Embodiment 1

FIG. 1 is an external view illustrating the structure of an airconditioning apparatus according to this invention. FIG. 2 is a partialcross-sectional view of the air conditioning apparatus of thisinvention. FIG. 3 is a longitudinal cross-sectional view of the airconditioning apparatus of this invention.

With referring to FIG. 1, FIG. 2 and FIG. 3, a reference numeral 10denotes the main body of the air conditioning apparatus of thisinvention the height of which is H. A reference numeral 10 a denotes ahousing. A reference numeral 11 a denotes a front air inlet grille and areference numeral 11 b denotes an upper air inlet grille. A referencenumeral 12 denotes a filter for removing floating dust in room air. Areference numeral 13 denotes a heat exchanger, a reference numeral 13 adenotes an aluminum fin and a reference numeral 13 b denotes a pipe. Areference 14 denotes an air outlet. A reference numeral 15 denotesblowing-direction changing vanes, a reference numeral 15 a denotes aleft/right vane and a reference numeral 15 b denotes an up/down vane. Areference numeral 1 denotes a cross flow fan. A reference numeral 2denotes the impeller of the cross flow fan. A reference numeral 3 adenotes a stabilizer. A reference numeral 3 b denotes a guide wall. Areference numeral 4 denotes a nozzle. A reference numeral 5 denotes afan motor for operating the impeller 2. A reference numeral 6 denotes arotating shaft. A reference numeral 8 denotes a box for electricequipment.

The thus configured main body of the air conditioning apparatus 10 isinstalled on a wall 17 of a room 18. The outside of the main body isformed by the housing 10 a and the detachable front air inlet grille 11a. Further, the housing 10 a is formed by the upper air inlet grille 11b, the guide wall 3 b near the back of the main body, and the nozzle 4in a lower front portion of the main body. The air outlet 14 is formedby the nozzle 4 and the guide wall 3 b. The nozzle 4 is formed in such amanner as to incorporate the stabilizer 3.

Besides, the front air inlet grille 11 a, the upper air inlet grille 11b and the filter 12, and furthermore, the heat exchanger 13 are disposedon the air inlet side of the cross flow fan 1. Then, the box forelectric equipment 8 stores an electrical substrate for controlling theblowing-direction changing vanes 15 and the fan motor 5.

FIG. 4 is a perspective view of the cross flow fan. FIG. 5 is alongitudinal cross-sectional view of the cross flow fan, where φD2indicates the outside diameter of the impeller. Referring now to thecross flow fan 1 shown in FIG. 4 and FIG. 5, a reference numeral 2 adenotes impeller units, a reference numeral 2 b denotes a vane of theimpeller 2, and a reference numeral 2 c denotes a ring of the impeller2. The cross flow fan 1 is formed by the impeller 2, the guide wall 3 band the stabilizer 3 a. The impeller 2 is formed by connecting aplurality of impeller units 2 a in the direction of the shaft, eachimpeller unit being formed by a plurality of vanes 2 b and the ring 2 cfor supporting the plurality of vanes. The guide wall 3 b surrounds theimpeller 2 in such a manner as to cover one side of the peripheralsurface of the impeller for guiding the flow of air blown off from theimpeller 2 to the air outlet 14. The stabilizer 3 a is placed in such amanner as to face the guide wall 3 b for controlling the position of acirculating vortex C1 which is generated inside the impeller 2 of thecross flow fan. The impeller 2 rotates and operates around the center ofthe rotating shaft 6 in the direction indicated by an arrow J. Stillmore, in this and the following embodiments, in a case where a magnesiumalloy, for example, is used as a material for the impeller 2, theimpeller will become recyclable.

Under this condition, an operation is to be started. When the impeller 2of the cross flow fan 1 is rotated and operated by the fan motor 5 asindicated by the arrow J of FIG. 2, air in the room 18 is sucked inthrough the front air inlet grille 11 a and the upper air inlet grille11 b, then passes through the filter 12 where floating dust in the roomair is removed, then is refrigerated or heated by the heat exchanger 13,and then sucked into the impeller 2. The air blown off from the impeller2 is blown off upward/downward and leftward/rightward into the room 18through the up/down vane 15 b and the left/right vane 15 a,respectively, provided at the air outlet 14.

In the case of no change being made with the height H of the main body10 of the thus described air conditioning apparatus, as the outsidediameter φD2 of the impeller corresponding to the outside diameter ofthe ring of the impeller 2 of the cross flow fan becomes larger, thenoise level is lowered at the same flow rate. In addition, the staticair pressure of the impeller 2 becomes high. Therefore, even if theventilating resistance is added on the air inlet side, the fancharacteristic does not becomes worse easily. However, if the outsidediameter φD2 of the impeller is too large, an interference occurs withthe heat exchanger 13. Besides, the length L14 of the air outlet 14becomes too short for the fan, and the flow of blown air becomesunstable. As a result, surging may be caused for the worst so that thenoise level is increased. In addition to that, the air of the room 18flows backwards towards the air outlet 14, so that dew is condensed whencooling. Furthermore, it causes the detachment of the flow of air on thesurface of the vane 2 b, which causes such singular noise Sm in a lowfrequency range as that discussed with reference to FIG. 54 in theconventional example. To the contrary, in the case that the outsidediameter φD2 of the impeller is too small, it is required to rotate theimpeller at a high rate in order to supply blowing wind at the same flowrate as that described above. In that case, the impeller 2 vibrates,thereby shaking the air conditioning apparatus, which may cause a fearof the air conditioning apparatus falling down in the end. In additionto that, the noise level is severely increased. Furthermore, an increasein the pressure of the impeller 2 is small, therefore if a resistance isadded on the air inlet side, a decrease in the flow rate becomes extremeat the same rotational frequency. Still more, as the outside diameterφD2 of the impeller is increased or reduced, the size of the guide wall3 b and the size of the nozzle 4 incorporating the stabilizer 3 a isincreased or reduced, respectively, in a similar manner.

Hence, there is an optimal range for the relationship between the heightH of the main body of the air conditioning apparatus 10 and the outsidediameter φD2 of the impeller.

FIG. 6 is a diagram illustrating the noise level SPL[dBA] in relation tothe ratio H/φD2 of the outside diameter φD2 of the impeller to theheight H of the main body. As shown in FIG. 6, if the ratio H/φD2 is 2.2or above and 3.0 or below, the noise level changes only a little.

In the case of applying the ratio of the above ratio H/φD2 to an airconditioning apparatus, it is particularly effective to apply the ratioto a wall-mounted type of an air conditioning apparatus. The height H ofthe main body of the air conditioning apparatus should be between 240 mmand 310 mm, therefore it is low in height and compact, which is one ofthe product values of the air conditioning apparatus.

Furthermore, if the outside diameter φD2 of the impeller is too largeand the ratio H/φD2 is too small, then the suction resistance of theimpeller 2 becomes high, so that the singular noise Sm is generated.

As shown in a diagram illustrating the ratio H/φD2 and a maximum noiselevel Sw[dBA] of the singular noise Sw of FIG. 7, when H/φD2 is 2.2 ormore, the singular noise Sm is small, therefore a favorable atmospheremay be achieved to the ear.

Still more, a mixture of plastic and grass fiber, for example, used as amaterial for a conventional impeller may not be used for the impeller 2.If a magnesium alloy is used, instead, as the magnesium alloy is morerefractory, the strength of the product will be preserved even if aheating source such as a heater is placed near the impeller 2.

AS aforementioned, when cooling, dew does not condense at the airoutlet, the noise level does not change much, and shaking is only small.In addition to that, no singular noise is generated, and even if theresistance in the passage of air on the air inlet side becomes high, theflow rate may be lowered only a little. Thus, an air conditioningapparatus which is reliable with a stable operation and silent with afavorable atmosphere to the ear may be obtained.

Embodiment 2

FIG. 8 is a diagram illustrating the shape of a vane 2 b of the impellerof a cross flow fan to be used as an air blowing means for an airconditioning apparatus of a second embodiment of the present invention.It is to be noted that elements other than the vane 2 b of thisembodiment are the same as those of the air conditioning apparatus andthe cross flow fan of FIG. 1 to FIG. 5 discussed in the firstembodiment, therefore the same reference numerals as those of theembodiment are assigned to those elements and then the description willbe omitted.

With referring to a cross-sectional shape of the vane 2 b of FIG. 8, areference numeral A20 denotes a tip of a vane's peripheral end portionA2 of the vane 2 b. A reference numeral A10 denotes a tip of a vane'sinternal circumferential end portion A1 of the vane 2 b. A referencemark O denotes the center of the rotating shaft of the impeller 2 of thecross flow fan, and a reference numeral O1 denotes the center of acamber line P0 formed in a single circular arc, the camber line beingthe center line of the thickness of the vane 2 b. A reference numeral P2denotes a pressure face of the vane 2 b on a side facing the directionof rotation of the impeller, and a reference numeral P3 denotes asuction surface opposing to the pressure face P2. Further, O-A20indicates a first straight line connecting the tip of the vane'speripheral end portion A20 of the vane 2 b and the center O, and O1-A20indicates a second straight line connecting the tip of the vane'speripheral end portion A20 of the vane 2 b and the center O1 of thecamber line P0. Further, a reference mark n denotes a firstperpendicular of the first straight line O-A20 to the tip of the vane'speripheral end portion A20, a reference mark m denotes a secondperpendicular line of the second straight line O1-A20 to the tip of thevane's peripheral end portion A20. An exit angle β2 is an acute angleformed by the first perpendicular and the second perpendicular.

Furthermore, the ratio H/φD2 of the height H of the main body of the airconditioning apparatus to the outside diameter φD2 of the impeller is2.2 or above and 3.0 or below.

As the exit angle β2 of FIG. 8 becomes larger, a distance between vanesδ is more extended, where the distance δ is the diameter of a circlecoming in contact with the respective surfaces of the pressure face P2of the vane 2 b and the suction surface P3 of the next vane 2 b.Consequently, when the flow of air passes between vanes, the ventilatingresistance becomes low. Therefore, the shaft power for operating theimpeller 2 is reduced, which allows the power consumption of the motorto be reduced.

However, if the exit angle β2 is too large, then the suction air of theimpeller 2 detaches at the peripheral end portion A2 of the vane 2 b asshown in FIG. 9, and the impeller is caused to stall. As a result, themovement of the impeller 2 of the cross flow fan becomes unstable, whichmay cause the wind blown off from the air outlet 14 of the airconditioning apparatus 10 to flow backwards into the impeller 2.

To the contrary, if the exit angle β2 is too small, then the distancebetween vanes δ is reduced. Consequently, when the flow of air passesbetween the vanes, the ventilating resistance becomes high. As a result,the shaft power for operating the impeller 2 is increased, therebyincreasing the power consumption of the motor.

Hence, there is an optimal range for the exit angle β2 to achieve thesituation that the movement of the impeller 2 become stable and theshaft power is reduced so that the power consumption of the motor isreduced.

FIG. 10 shows the relationship between the exit angle β2 of the vane andthe power consumption Wm[W] of the motor. As shown in FIG. 10, if theexit angle β2 is at least between 23 degrees and 30 degrees, anenergy-saving air conditioning apparatus which achieves a reducedconsumption of the motor power may be obtained.

Embodiment 3

FIG. 11 is a diagram illustrating the shape of a vane 2 b of theimpeller of a cross flow fan to be used as an air blowing means for anair conditioning apparatus according to a third embodiment of thepresent invention. It is to be noted that elements other than the vane 2b in this embodiment are the same as those of the air conditioningapparatus and the cross flow fan of FIG. 1 to FIG. 5 discussed above inthe first embodiment, therefore the same reference numerals as those ofthe embodiment are assigned to the elements and then the descriptionwill be omitted.

With referring to a cross-sectional shape of the vane 2 b of FIG. 11,the reference numeral A20 denotes the tip of the vane's peripheral endportion A2 of the vane 2 b. The reference numeral A10 denotes the tip ofthe vane's internal circumferential end portion A1 of the vane 2 b. Thereference mark O denotes the center of the rotating shaft of theimpeller 2 of the cross flow fan, and the reference numeral O1 denotesthe center of the camber line P0 formed into a single circular arc, thecamber line being the center line of the vane 2 b in the direction ofthe thickness. The reference numeral P2 denotes the pressure face of thevane 2 b on a side facing the direction of rotation of the impeller, andthe reference numeral P3 denotes the suction surface opposing to thepressure face P2. Further, O-A20 indicates the first straight lineconnecting the tip of the vane's peripheral end portion A20 of the vane2 b and the center O, and O1-A20 indicates the second straight lineconnecting the tip of the vane's peripheral end portion A20 of the vane2 b and the center O1 of the camber line P0. Further, the reference markn denotes a first perpendicular of the first straight line O-A20 to thetip of the vane's peripheral end portion A20, the reference mark mdenotes a second perpendicular line of the second straight line O1-A20to the tip of the vane's peripheral end portion A20. The exit angle 2 isan acute angle formed by the first perpendicular and the secondperpendicular. Furthermore, the maximum thickness of the vane 2 b aroundthe center is tm and the thickness of the vane's peripheral end portion,which is the diameter of the circular-arc shaped vane's end portion A2and the minimum thickness, is t2.

Further, the ratio H/φD2 of the height H of the main body of the airconditioning apparatus to the outside diameter φD2 of the impeller is2.2 or above and 3.0 or below. Furthermore, the exit angle β2 is withina range from 23 degrees to 30 degrees.

With referring to FIG. 11, the maximum thickness tm is not changed andthe thickness of the vane's peripheral end portion t2, which is thevane's minimum thickness, is reduced. Otherwise, the thickness t2 of thevane's peripheral end portion, which is the vane's minimum thickness, isnot changed, and the vane's maximum thickness tm is increased. In otherwords, a thickness ratio tm/t2, which is the ratio of the vane's maximumthickness tm to the vane's minimum thickness t2, is increased.

However, in the case of the vane 2 b of the impeller 2 of theconventional cross flow fan, the thickness ratio tm/t2 of which is smalland the exit angle β2 of which is 23 degrees or more as shown in FIG.53, if the ventilating resistance is increased due to such as dustaccumulating on the filter 12 of the body 10 of the air conditioningapparatus, when the vane 2 b passes through an area F1 on the air inletside of the impeller 2 and also in an upper front portion of the mainbody of the air conditioning apparatus 10, detachment is caused at thevane's peripheral end portion A2 of the vane 2 b influenced by an inflowof suction air from the back side of the air conditioning apparatus 10.Then, a detaching vortex G1 is generated in the vicinity of the vane'ssuction surface P3, and also the flow rate is increased in the vicinityof the pressure face P2 of the next vane 2 b. This causes singular noiseSm having a broad frequency band in a low frequency range to begenerated as shown in FIG. 54.

As discussed above in this invention, by increasing the vane's thicknessratio tm/t2, the curvature of the vane's suction surface P3 isincreased, which makes it difficult to detach. As a result, the rate offlow between the vane 2 b and the next vane 2 b becomes flat. In such asituation, no singular noise Sm will be generated.

However, if the thickness ratio tm/t2 is too large, the distance δbetween vanes, which is the diameter of a circle coming in contact withboth of the vane 2 b and the next vane 2 b, becomes narrow, and theventilating resistance between the vanes is increased. As a result, thenoise level at the same flow rate becomes aggravated. Hence, there is anoptimal range for the thickness ratio.

FIG. 12 is a diagram illustrating a change in the level Sw[dBA] of thesingular noise Sm when the thickness ratio tm/t2 is varied in the caseof no dust accumulated on the filter 12 and in the case of dustaccumulated on the filter 12. FIG. 13 is a diagram illustrating a changein the noise level SPL[dBA] at the same flow rate when the thicknessratio tm/t2 is varied, in the cases of the filter 12 with and withoutdust accumulated, which is similar to the diagram of FIG. 12.

With referring to FIG. 12, in the case of no dust accumulated on thefilter 12, if the thickness ratio is 1.4 or more, then the singularnoise Sm becomes low noise. In the case of dust accumulated on thefilter 12, if the thickness ratio is 1.5 or more, the singular noisebecomes low noise. Further, with reference to FIG. 13, when the filter12 has no dust accumulated, if the thickness ratio is 1.4 or above and3.5 or below, the noise level is low. With dust accumulated, if thethickness ratio is 1.5 or above and 4.0 or below, the noise level islow.

Thus, according to FIG. 12 and FIG. 13, if the thickness ratio tm/t2 isat least 1.5 or above and 3.5 or below, the singular noise Sm becomeslow noise, and the noise level is not aggravated.

As a result, even if the ventilating resistance is increased due to suchas dust accumulated on the filter 12 of the air conditioning apparatus,an air conditioning apparatus which provides a favorable atmosphere tothe ear may be obtained.

Embodiment 4

FIG. 14 is a diagram illustrating the shape of a vane 2 b of theimpeller of a cross flow fan to be used as an air blowing means for anair conditioning apparatus according to a fourth embodiment of thepresent invention. It is to be noted that elements other than the vane 2b in this embodiment are the same as those of the air conditioningapparatus and the cross flow fan of FIG. 1 to FIG. 5 discussed above inthe first embodiment, therefore the same reference numerals as those ofthe embodiment are assigned to the elements and the description will beomitted.

With referring to a cross-sectional shape of the vane 2 b of FIG. 14,the reference numeral A20 denotes the tip of the vane's peripheral endportion A2 of the vane 2 b. The reference numeral A10 denotes the tip ofthe vane's internal circumferential end portion A1 of the vane 2 b. Thereference mark O denotes the center of the rotating shaft of theimpeller 2 of the cross flow fan, and the reference numeral O1 denotesthe center of the camber line P0 formed into a single circular arc, thecamber line being the center line of the vane 2 b in the direction ofthe thickness. The reference numeral P2 denotes the pressure face of thevane 2 b on a side facing the direction of rotation of the impeller, andthe reference numeral P3 denotes the suction surface opposing to thepressure face P2. Further, O-A20 indicates the first straight lineconnecting the tip of the vane's peripheral end portion A20 of the vane2 b and the center O, and O1-A20 indicates the second straight lineconnecting the tip of the vane's peripheral end portion A20 of the vane2 b and the center O1 of the camber line P0. Further, the reference markn denotes the first perpendicular of the first straight line O-A20 tothe tip of the vane's peripheral end portion A20, the reference mark mdenotes the second perpendicular line of the second straight line O1-A20to the tip of the vane's peripheral end portion A20. The exit angle β2is an acute angle formed by the first perpendicular and the secondperpendicular. Furthermore, a maximum thickness of the vane 2 b aroundthe center is tm and the thickness of a vane's peripheral end portion,which is the diameter of the circular-arc shaped vane's end portion A2and a minimum thickness, is t2.

With reference to the impeller 2 of a cross flow fan having the ratioH/φD2 of the outside diameter φD2 of the impeller 2 of the cross flowfan to the height H of the air conditioning apparatus 2.2 or above and3.0 or below, according to the impeller of the conventional cross flowfan, the vane's maximum thickness tm is between 0.9 mm and 1.5 mm, andthe vane's minimum thickness t2, which is the diameter of thecircular-arc shaped vane's peripheral end portion, is 0.64 mm. Accordingto the impeller 2 of the cross flow fan to be mounted in the airconditioning apparatus 10 of this invention, the vane's minimumthickness t2, which is the diameter of the circular-arc shaped vane'speripheral end portion, is between 0.2 mm and 0.5 mm. Thus, by makingthe thickness t2 of the vane's peripheral end portion at least thinnerthan that of the conventional case, the stagnation of the flow ofsuction air is reduced at the vane's peripheral end portion A2 as shownin FIG. 15, which allows to reduce the loss. As a result, the shaftpower for operating the impeller 2 by the fan motor 5 is reduced, whichallows to reduce the power consumption of the fan motor 5 as shown inFIG. 16. FIG. 16 is a diagram illustrating the relationship between thevane's minimum thickness t2 and the motor power consumption Wm[W].

Furthermore, if the air conditioning apparatus 10 operates for a longtime so that the impeller 2 is rotated and operated for a long time,minute dust which has left unremoved by the filter 12 is accumulated onthe vane's peripheral end portion A2 of the impeller 2 as shown in FIG.17. Consequently, the distance between vanes δ is reduced, and the flowrate Q[m³/min] in the same fan rotational frequency is decreased as theoperating time passes. FIG. 18 is a diagram illustrating the operatingtime and the air flow drop rate ΔQ in the same rotational frequency inthe case of the conventional cross flow fan and in the case of the crossflow fan of this invention. As shown in FIG. 18, by making the thicknesst2 of the vane's peripheral end portion of the impeller thinner thanthat of the conventional case, the air flow drop rate in the sameoperating time may be minimized. As a result, such a problem may besolved that although the air conditioning apparatus has been operatingfor quite a long time, it does not still get warm enough when heating,and it does not still get cool enough when cooling. In addition to that,a cleaning cycle tc[hour] may become longer than the cleaning cycletc0[hour] of the conventional case. Consequently, the frequency ofcleaning may be reduced.

Thus, by forming the vane as described above in this invention, anenergy-saving and highly reliable air conditioning apparatus having lowpower consumption may be obtained.

Embodiment 5

FIG. 19 is a diagram illustrating a basic vane form of the shape of avane 2 b of the impeller 2 of a cross flow fan to be used as an airblowing means for an air conditioning apparatus according to a fifthembodiment of the present invention. FIG. 20 is an enlarged view of avane's peripheral end portion A20 of the fifth embodiment which has achange in the shape of the vane's peripheral end portion A20 in thebasic vane form of FIG. 19. It is to be noted that elements other thanthe vane 2 b in this embodiment are the same as those of the airconditioning apparatus and the cross flow fan of FIG. 1 to FIG. 5discussed above in the first embodiment, therefore the same referencenumerals as those of the embodiment are assigned to the elements and thedescription will be omitted.

With referring to a cross-sectional shape of the vane 2 b of FIG. 19,which is the basic vane form of the fifth embodiment, the referencenumeral A20 denotes the tip of the vane's peripheral end portion A2 ofthe vane 2 b. The reference numeral A10 denotes the tip of the vane'sinternal circumferential end portion A1 of the vane 2 b. The referencemark O denotes the center of the rotating shaft of the impeller 2 of thecross flow fan, and the reference numeral O1 denotes the center of thecamber line P0 formed into a single circular arc, the camber line beingthe center line of the vane 2 b in the direction of the thickness. Thereference numeral P2 denotes the pressure face of the vane 2 b on a sidefacing the direction of impeller rotation, and the reference numeral P3denotes the suction surface opposing to the pressure face P2. Further,O-A20 indicates the first straight line connecting the tip of the vane'speripheral end portion A20 of the vane 2 b and the center O, and O1-A20indicates the second straight line connecting the tip of the vane'speripheral end portion A20 of the vane 2 b and the center O1 of thecamber line P0. Further, the reference mark n denotes the firstperpendicular of the first straight line O-A20 to the tip of the vane'speripheral end portion A20, the reference mark m denotes the secondperpendicular line of the second straight line O1-A20 to the tip of thevane's peripheral end portion A20. The exit angle β2 is an acute angleformed by the first perpendicular and the second perpendicular.

According to this invention, the vane 2 b is formed into a sharp edge atthe vane's peripheral end portion A2. This shape is obtained by excisingthe vane 2 b of FIG. 19 along a circle passing through the tip A20 ofthe vane's peripheral end portion, the center of the circle being thecenter O of the rotating shaft of the impeller 2 as shown in FIG. 20.

Thus, by forming the vane 2 b as described above in this invention, suchstagnation of air flow caused at the tip A20 of the vane's peripheralend portion as that shown in a state of air flow at the circular-arcshaped vane's peripheral end portion A2 of the conventional vane 2 b ofFIG. 21 is reduced, and the loss is reduced. For that reason, the shaftpower for operating the impeller 2 is more reduced. As a result, thepower consumption of the motor may be minimized as shown in a diagramillustrating the power consumption Wm[W] of the fan motor 5 foroperating the impeller of the cross flow fan in each case of theconventional example and this invention for comparison. Consequently, ahighly energy-saving air conditioning apparatus may be obtained with thepower consumption being reduced.

Embodiment 6

FIG. 23 is a longitudinal cross-sectional view of an air conditioningapparatus 10 and the impeller 2 of a cross flow fan of this invention.The ratio H/φD2 of the height H of the main body of the air conditioningapparatus to the outside diameter φD2 of the impeller is 2.2 or aboveand 3.0 or below. Spaces λ between the vanes 2 b of the impeller 2 areirregular in pitch (λ1, λ2, λ3, . . . ). The cross-sectional shape ofthe vane 2 b of the impeller 2 of the cross flow fan of FIG. 23 is theshape discussed in the third embodiment, for example. It is to be notedthat elements other than the impeller 2 of the cross flow fan of thisembodiment are the same as those of the air conditioning apparatus andthe cross flow fan of FIG. 1 to FIG. 5 discussed above in the firstembodiment, therefore the same reference numerals as those of theembodiment are assigned to the elements and the description will beomitted.

FIG. 24 is a diagram illustrating the frequency characteristic of noiseof an air conditioning apparatus in which the conventional cross flowfan is mounted. For example, in a case where the singular noise Sm isgenerated in the impeller 2 of the conventional cross flow fan, thesingular noise Sm is multiplexed, and the frequency characteristic isformed into a sharp pointed shape when the width of the generatingfrequency fs of the singular noise Sm is around 100[Hz]. This is becausethe spaces λ between vanes 2 b and the next vanes 2 b are regular, whenthe singular noise Sm is generated, the flow rate of air and the stateof the detaching vortex are almost regular at the vane 2 b.

However, according to the air conditioning apparatus in which the crossflow fan of this invention is mounted, as shown in FIG. 23, the spaces λbetween the vanes 2 b are irregular in pitch. Therefore, when thesingular noise Sm is generated at each vane 2 b, the flow rate of airand the state of a detaching vortex at the vane 2 b differ from others.As a result, as shown in a diagram illustrating the frequencycharacteristic of noise of the air conditioning apparatus in which thecross flow fan of this invention is mounted of FIG. 25, the singularnoise Sm is dispersed. The width of the generating frequency fs of thesingular noise Sm becomes broadband. Furthermore, the generating levelSw[dBA] of the singular noise Sm is lowered, and then the singular noisedisappears from the diagram of the frequency characteristic, and cannotbe heard in the end.

Furthermore, as shown in FIG. 26, in a case where the pipes 13 b of theheat exchanger 13 are closely disposed to the impeller 2, the trailingvortexes G2 of the pipes 13 a are directly sucked into the impeller 2.In that case, rotational noise (NZ sound) is also generated by aninstantaneous pressure fluctuation caused at the vane's peripheral endportion A2 of the vane 2 b.

In such a case, as shown in the diagrams of FIG. 24 and FIG. 25illustrating the frequency characteristic of the air conditioningapparatus of the conventional example and that of this embodiment,respectively, in the case of the impeller 2 of the conventional crossflow fan, because an instantaneous lift fluctuation at the vane'speripheral end portion A2 is the same at each vane 2 b, the rotationalnoise is multiplexed, therefore a peak level becomes high in a narrowband. However, if the space λ between the vanes 2 b is irregular inpitch, then the instantaneous lift fluctuation at the vane's peripheralend portion A2 is dispersed. As a result, the generating frequency ofthe rotational noise is dispersed and not multiplexed. Consequently, thepeak level becomes low.

With further reference to the conventional cross flow fan in which thevanes 2 b are fitted at regular intervals, if gaps δs and δG between theimpeller 2 and the closest point of the stabilizer 3 a to the impellerand the closest point of the guide wall 3 b to the impeller,respectively, are small, then the rotational noise (NZ sound) isgenerated by the instantaneous pressure fluctuation in those gaps.However, by fitting the vanes 2 b in the irregular pitch according tothis embodiment, the instantaneous lift fluctuation at the vane'speripheral end portion A2 is dispersed. As a result, the generatingfrequency of the rotational noise is dispersed and not multiplexed, sothat the peak level becomes low. For that reason, the gaps δs and δG canbe minimized until the peak level becomes the same as that of theconventional case, so that the static air pressure of the impeller 2 maybe raised. As a result, a fan rotational frequency N[r.p.m] at the sameflow rate Q[m³/min] maybe lowered. Consequently, the power consumptionmay be reduced as shown in a diagram illustrating the relationship inthe power consumption Wm[W] of the fan motor at the same flow rateQ[m³/min] of FIG. 27.

Thus, by forming the impeller of the cross flow fan as discussed abovein this embodiment, the singular noise and the rotational noise maybecome low, and in addition, the power consumption of the fan motor maybe reduced. Consequently, an energy-saving as well as silent airconditioning apparatus which provides a favorable atmosphere to the earmay be obtained.

Embodiment 7

FIG. 28 is a longitudinal cross-sectional view of an air conditioningapparatus according to a seventh embodiment of this invention. It is tobe noted that the main part of the configuration of the air conditioningapparatus of this embodiment is the same as that discussed withreference to FIG. 1 to FIG. 5 in the first embodiment.

With referring to FIG. 28, the reference numeral 10 denotes the mainbody of the air conditioning apparatus of this invention the height ofwhich is H. The reference numeral 101 a denotes the housing. Thereference numeral 11 a denotes the front air inlet grille and thereference numeral 11 b denotes the upper air inlet grille. The referencenumeral 12 denotes the filter for removing dust. The reference numeral13 denotes the heat exchanger, the reference numeral 13 a denotes thealuminum fin and the reference numeral 13 b denotes the pipe. Thereference 14 denotes the air outlet. The reference numeral 15 denotesthe blowing-direction changing vane, the reference numeral 15 a denotesthe left/right vane and the reference numeral 15 b denotes the up/downvane. The reference numeral 1 denotes the cross flow fan. The referencenumeral 2 denotes the impeller of the cross flow fan. The referencenumeral 3 a denotes the stabilizer. The reference numeral 3 b denotesthe guide wall. The reference numeral 4 denotes the nozzle.

The outside of the main body of the thus configured air conditioningapparatus 10 is formed by the housing 10 a and the detachable front airinlet grille 11 a. Further, the housing 10 a is formed by the upper airinlet grille 11 b, the guide wall 3 b near the back, and the nozzle 4 atthe lower front portion. The air outlet 14 is formed by the nozzle 4 andthe guide wall 3 b. Furthermore, the nozzle 4 is formed in such a manneras to incorporate the stabilizer 3.

Further, on the air inlet side of the cross flow fan 1, the front airinlet grille 11 a, the upper air inlet grille 11 b and the filter aredisposed, and the heat exchanger 13 is also disposed.

It is to be noted that the ratio of the height H of the main body of theair conditioning apparatus to the outside diameter φD2 of the impeller 2is 2.2 or above and 3.0 or below.

Referring now to the air conditioning apparatus thus configured, astraight line connecting the closest point 3 a ₁, of the stabilizer 3 ato the impeller 2 of the cross flow fan and the center O of the rotatingshaft of the impeller is O-3 a ₁, and a horizontal line passing throughthe center O of the rotating shaft of the impeller is L0. In such acase, the stabilizer is formed in such a manner as to locate at a placewhere an acute angle θ1 formed by the two straight lines 0-3 a ₁ and L0is between 30 degrees and 70 degrees from the horizontal line L0 as thebase in the opposite direction to the rotation of the impeller.

FIG. 29 shows a conventional air conditioning apparatus in which theacute angle θ1 is more than 70 degrees, and the closest point 3 a ₁ ofthe stabilizer to the impeller 2 of the cross flow fan is disposed at alower portion of the air conditioning apparatus. In this case, acirculating vortex Cl moves downwards, so that an air inlet side area Fiis expanded. However, a suction air flow E1 flows into an area F1located on the air inlet side of the impeller 2 and also in an upperfront portion of the main body of the air conditioning apparatus 10. Forthat reason, when the vane 2 b passes through the area F1, air mayeasily detach at the vane's peripheral end portion A2 of the vane 2 b.For that reason, if the ventilating resistance is increased due to suchas dust accumulated on the filter 12, in particular, a detaching vortexG1 is generated in the vicinity of the suction surface P3 of the vane.In addition to that, the flow rate in the vicinity of the pressure faceP2 of the following vane 2 b is increased. As a result, as shown in FIG.30, the singular noise Sm having a broad frequency band is generated ina low frequency range.

In a diagram illustrating a change in the singular noise level Sw[dBA]in relation to the θ1 of FIG. 31, if θ1 is at least 70 degrees or less,there will be no problem with the singular noise Sm.

Further, as shown in FIG. 32, in a case where the acute angle θ1 is 30degrees or less, the singular noise Sm is reduced, but the air inletside area Fi is too narrow, therefore the flow rate of suction air isincreased. As a result, as shown in FIG. 33, the noise level SPL[dBA] atthe same flow rate is increased rapidly.

According to FIG. 31 and FIG. 33, when a straight line connecting theclosest point 3 a ₁ of the stabilizer 3 a to the impeller 2 of the crossflow fan and the center O of the rotating shaft of the impeller is O-3 a₁, and a horizontal line passing through the center O of the rotatingshaft of the impeller is L0, if the acute angle θ1 formed by the twostraight lines O-3 a ₁ and L0 is 30 degrees or above and 70 degrees orbelow, the singular noise becomes low noise and the noise level is low.

Thus, by forming the stabilizer 3 a as discussed above, a low-noise airconditioning apparatus which provides a favorable atmosphere to the earwithout generating the singular noise.

Embodiment 8

FIG. 34 is a longitudinal cross-sectional view of an air conditioningapparatus according to an eighth embodiment. It is to be noted that themain part of the configuration of the air conditioning apparatus of thisembodiment is the same as that of the air conditioning apparatus and thecross flow fan discussed above with reference to FIG. 28 in the seventhembodiment, therefore the same reference numerals as those of theembodiment are assigned to elements and the description will be omitted.

It is further to be noted that the ratio of the height H of the mainbody of the air conditioning apparatus to the outside diameter θφD2 ofthe impeller 2 is 2.2 or above and 3.0 or below in this embodiment.

With referring to the cross flow fan 1 of the air conditioning apparatus10 of FIG. 34, the reference numeral 2 b denotes a vane of the impeller2, and the reference numeral 2 c denotes a ring of the impeller 2. Thecross flow fan 1 is formed by the impeller 2, the outside diameter ofwhich is φD2 , the guide wall 3 b which surrounds the impeller 2 in sucha manner as to cover one portion of the peripheral surface of theimpeller 2 so that the flow of air blown off from the impeller 2 isguided to the air outlet 14, and the stabilizer 3 a which is placed insuch a manner as to face the guide wall 3 b for controlling the positionof the circulating vortex C1 generated inside the impeller 2 of thecross flow fan. The impeller 2 rotates and operates about the center Oof the rotating shaft in the direction of arrow J.

Further, the stabilizer is formed in such a manner that an acute angleθ2 formed by the two straight lines 0-3 a ₁ and O-3 a ₂ is between 15degrees and 40 degrees, where the straight line O-3 a ₁ connects thecenter O of the rotating shaft of the impeller 2 of the cross flow fanand the closest point 3 a ₁ of the stabilizer to the impeller of thecross flow fan and the straight line O-3 a ₂ connects the center O ofthe rotating shaft of the impeller 2 of the cross flow fan and a lowerend 3 a ₂ of the stabilizer.

Thus, by forming the stabilizer 3 a as discussed above, the movement ofthe circulating vortex C1 which is generated inside the impeller 2 ofthe cross flow fan may be kept stable if the ventilating resistance inthe air inlet side area Fi is increased due to such as dust accumulatedon the filter 12. If the acute angle θ2 is too small, then thestabilizer 3 a cannot control the movement of the circulating vortex C1when the ventilating resistance in the air inlet side area F1 isincreased. As a result, the flow of blown air becomes unstable. For thatreason, humid room air flows towards the refrigerated air outlet 14, anddew is condensed on the surfaces of the nozzle 4 and the guide wall 3 bat the air outlet 14 when cooling. Furthermore, when the air movesbackward from an air outlet side area Fo to the air inlet side area Fi,if θ2 is too small, then the air pressure at the stabilizer 3 a rapidlyfluctuates, so that the noise level is increased as shown in FIG. 35.Besides, if the acute angle θ2 is too large, then the areas Fi and Fo onthe air inlet side and the air outlet side, respectively, become narrow,so that the ventilating resistance is increased. For that reason, theventilating characteristic becomes worse and the noise aggravates at thesame flow rate. In addition to that, the power consumption Wm[W] of thefan motor is increased as shown in FIG. 36.

As shown in FIG. 35 and FIG. 36, if the stabilizer is formed in such amanner that the acute angle θ2 is at least between 15 degrees and 40degrees, then no dew will be condensed when cooling if such as dust isaccumulated on the filter. In addition to that, a change in the noiselevel will become small, and the power consumption of the fan motor 5will be reduced. For that reason, a highly reliable and energy-savingair conditioning apparatus may be obtained.

Embodiment 9

FIG. 37 is a longitudinal cross-sectional view of an air conditioningapparatus according to a ninth embodiment. It is to be noted thatelements other than the cross flow fan 1 of the air conditioningapparatus of this embodiment are the same as those of the airconditioning apparatus and the cross flow fan of FIG. 1 to FIG. 5discussed above in the eighth embodiment, therefore the same referencenumerals as those of the embodiment are assigned to the elements and thedescription will be omitted.

With referring to the cross flow fan 1 of the air conditioning apparatusof FIG. 37, the reference numeral 2 b denotes a vane of the impeller 2and the reference numeral 2 c is a ring of the impeller 2. The crossflow fan 1 is formed by the impeller 2, the outside diameter of which isφD2 , which is formed by a plurality of units 2 a being connected in thedirection of the shaft, each unit being formed by a plurality of vanes 2b and the ring 2 c for supporting the plurality of vanes, the guide wall3 b which surrounds the impeller 2 in such a manner as to cover oneportion of the peripheral surface of the impeller 2 so that the flow ofair blown off from the impeller 2 is guided to the air outlet 14, andthe stabilizer 3 a which is placed in such a manner as to face the guidewall 3 b for controlling the position of the circulating vortex C1generated inside the impeller 2 of the cross flow fan. The impeller 2rotates and operates around the center O of the rotating shaft in thedirection of arrow J.

It is to be noted that the ratio of the height H of the main body of theair conditioning apparatus to the outside diameter φD2 of the impeller 2is 2.2 or above and 3.0 or below.

Further, a closest point 3 b ₁ of the guide wall 3 b to the impeller 2of the cross flow fan is disposed at an upper rear portion of the airconditioning apparatus. In addition to that, the guide wall 3 b isformed in such a manner that an angle θ3 formed by a straight line O-3 b₁, which connects the closest point 3 b ₁ of the guide wall 3 b to theimpeller and the center O of the rotating shaft of the impeller, and ahorizontal line L0, which passes through the center O of the rotatingshaft of the impeller, is between 35 degrees to 80 degrees.

At the closest point 3 b ₁ of the guide wall 3 b to the impeller 2, theair inlet side area Fi and the air outlet side area Fo are separated inthe cross flow fan.

For that reason, if the angle θ3 is too large, then the guide wall 3 bis extended forward to a front portion of the air conditioning apparatus10 as shown in FIG. 38, so that the air inlet side area Fi of theimpeller becomes narrow. Because the area on the air inlet side becomesnarrow, the ventilating resistance becomes high. For that reason, theventilating characteristic becomes worse, the noise level is aggravated,and the power consumption Wm of the fan motor 5 is increased. Inaddition to that, the flow rate of the air flow E1 from the back side ofthe air conditioning apparatus is increased, and the singular noise Smis easily generated. On the other hand, if the angle θ3 is too small,then the guide wall 3 b becomes shorter as shown in FIG. 39. For thatreason, a flow E2 of blown-off air from the impeller 2 cannot recoverits static air pressure sufficiently at the guide wall 3 b, and becomesunstable. As a result, if the ventilating resistance becomes high due tosuch as dust accumulated on the filter 12, dew is condensed when coolingat the nozzle 4 of the air outlet 14 and in the vicinity of the guidewall 3 b. In addition to that, the noise level will become high.

FIG. 40 is a diagram illustrating a change in the noise level at thesame flow rate in a situation where the θ3 is varied. FIG. 41 is adiagram illustrating a change in the power consumption of the fan motorat the same flow rate in a situation where the θ3 is varied. By formingthe guide wall 3 b at the upper rear portion of the air conditioningapparatus in such a manner that the angle θ3 formed by the straight lineO-3 b ₁, which connects the closest point 3 b ₁ of the guide wall 3 b tothe impeller 2 of the cross flow fan and the center O of the rotatingshaft of the impeller, and the horizontal line L0, which passes throughthe center O of the rotating shaft of the impeller, is between 35degrees and 80 degrees, dew is not condensed when cooling and the powerconsumption is reduced. Moreover, the noise level is not increased. Forthat reason, a highly reliable and silent as well as energy-saving airconditioning apparatus may be obtained.

Embodiment 10

FIG. 42 and FIG. 43 are diagrams illustrating an example of the shape ofa vane 2 b of the impeller of a cross flow fan to be used as an airblowing means for an air conditioning apparatus according to a tenthembodiment of the present invention. Those figures are thecross-sectional view of the vane 2 b and the enlarged view of an area inthe vicinity of the peripheral end portion A2 of the vane 2 b. It is tobe noted that elements other than the vane 2 b in this embodiment arethe same as those of the air conditioning apparatus and the cross flowfan of FIG. 1 to FIG. 5 discussed above in the first embodiment,therefore the same reference numerals as those of the embodiment areassigned to the elements and the description will be omitted.

With referring to FIG. 42 and FIG. 43, a vane 2 ba is a remainingportion on the internal circumferential side of the impeller aftercutting the vane 2 b along a circle which shares the center of theimpeller 2 and has a reduced diameter φD21 by 2% from the diameter φD2of the peripheral circle of the ring 2 c which is also the outerdiameter of the impeller. Vertexes A22 and A23 and an arc A223 areobtained as a result of cutting the vane 2 b. Further, a straight lineconnecting the rotating center O of the impeller and the vertex A22 isO-A22, and a straight line connecting the rotating center O of theimpeller and the vertex A23 is O-A23. Further, straight lines obtainedby inclining the vertexes A22 and A23 by a fixed same angle θ on theside of the direction of rotation are U2 and U3, respectively. In thissituation, the vane 2 b is formed by the vane 2 ba and a portion 2 bb ina similar shape to a parallelogram. The portion 2 bb in a similar shapeto a parallelogram is enclosed by the two straight lines U2 and U3, thearc A223, and a circle having a diameter φD22 which is at least smallerthan the outside diameter φD2 of the impeller and larger than thediameter φD21 mentioned above.

Furthermore, the fixed angle θ is formed at least in such a manner as tobe smaller than an angle θ4 formed by a tangent U4 at the vertex A22 andthe straight line O-A22.

Thus, by forming the vane 2 b as discussed above, as shown in FIG. 44,the suction flow of air is a little detached at a segment U3 portion ofa vane 2 b′ placed in front of the vane 2 b in the direction ofrotation. However, a pressure is provided to the suction surface P3 ofthe previous vane 2 b′ by a segment U2 portion of the vane 2 b.Therefore, the main stream of the suction flow of air moves toward acenter portion of the passage of air between the vane 2 b and theprevious vane 2 b′. As a result, there is no air flow at a high rate nordetaching vortex appearing in the vicinity of the vane's surfaces P2 andP3. For that reason, if a high resistance such as a high collection dustremoving filer is disposed on the air inlet side of the air conditioningapparatus, the singular noise does not appear in a low frequency rangeand the noise level is lowered.

Embodiment 11

FIG. 45 is a diagram illustrating a shape of a vane 2 b of the impellerof a cross flow fan to be used as a air blowing means of an airconditioning apparatus according to an eleventh embodiment of thepresent invention. The figure is an enlarged diagram of an area in thevicinity of the peripheral end portion A2 of the vane 2 b. It is to benoted that elements other than the vane 2 b in this embodiment are thesame as those of the enlarged views of the vane 2 b of the impeller ofthe cross flow fan shown in FIG. 42 and FIG. 43 discussed above in thetenth embodiment, therefore the same reference numerals as those of thefigures are assigned to the elements and the description will beomitted.

With referring to FIG. 45, vertexes A24 and A25 of the portion similarto a parallelogram 2 bb of the peripheral end portion A2 of the vane 2 bof FIG. 43 discussed above face the periphery of the impeller 2. The twovertexes A24 and A25 are formed in a fixed shape of R.

Thus, the portion facing the periphery of the impeller 2 of the vane 2 bis not formed in the shape of an edge but the fixed shape of R (R=0.2 mmor more). This assures a safe cleaning of the impeller 2 without anyfear of tearing a cloth and cutting a finger while cleaning the vaneswith soft paper (such as waste).

Thus, by forming the shape of the vanes as discussed above in thisinvention, a safe air conditioning apparatus may be obtained even forcleaning.

Embodiment 12

FIG. 46 is a perspective view of an impeller of a cross flow fan to beused as an air blowing means for an air conditioning apparatus accordingto the present invention. It is to be noted that elements other than thevane 2 b in this embodiment are the same as those of the airconditioning apparatus and the cross flow fan of FIG. 1 to FIG. 5discussed above in the first embodiment, therefore the same referencenumerals as those of the embodiment are assigned to the elements and thedescription will be omitted.

As shown in FIG. 46, the plurality of vanes 2 b incorporated into asingle unit supported by the ring 2 c of the impeller 2 of the crossflow fan is inclined by a fixed angle θ1 to the center line O1 of therotating shaft of the fan.

Thus, by forming the impeller 2 of the cross flow fan as discussedabove, such problems as stated below will be solved. In a case where thevanes 101 b are provided in parallel to the rotating shaft 0 and thestabilizer 103 like the impeller 101 of the cross flow fan of theconventional air conditioning apparatus shown in FIG. 50 to FIG. 52,when the impeller 101 rotates and the vanes 101 b pass through an areain the vicinity of the stabilizer 103, one vane 101 b of each impellerunit 101 a passes through the same portion at the same timing. For thatreason, as shown in a diagram illustrating the frequency characteristicof FIG. 47, the pressure fluctuation is received at the same timing.Then, the pressure fluctuation level at the vane's peripheral endportion A2 is multiplied and to be increased, which generates rotationalnoise (NZ sound) and this poses a problem. Another problem is posed whenthe detaching vortex G1 generates the singular noise Sm at the vane 101b, the detaching vortex G1 occurs at the same timing in the direction ofthe length of the impeller unit 101 a. For that reason, such phenomenondoes not occur that the pressure fluctuation caused by the detachingvortex G1 is multiplied, thereby raising the noise level Sw of thesingular noise Sm. As shown in FIG. 48, when the vane 2 b passes throughan area in the vicinity of the stabilizer 3 a, the timing of each vane 2b of each impeller unit 2 a passing through the stabilizer 3 a differsfrom others in the direction of the length. For that reason, thegeneration timing of the pressure fluctuation at the peripheral endportion A2 of the vane 2 b differs from others. As a result, thepressure fluctuation level is lowered and the rotational noise isreduced. Therefore, even if the detaching vortex G1 occurs, because thetiming of generating the detaching vortex G1 is different from others inthe direction of the length, the pressure fluctuation caused by thedetaching vortex G1 is dispersed, so that the noise level Sw of thesingular noise Sm may be lowered.

Furthermore, if the cross-sectional shape of the vane 2 b has such shapeas that shown in FIG. 42 discussed in the tenth embodiment, the singularnoise is not generated. Therefore, a higher collection dust removingfilter may be installed.

Embodiment 13

FIG. 49 is a diagram illustrating a shape of a vane 2 b of the impellerof a cross flow fan to be used as an air blowing means for an airconditioning apparatus according to a thirteenth embodiment of thepresent invention. The figure is a partial cross-sectional view of theimpeller 2. It is to be noted that elements other than the vane 2 b inthis embodiment are the same as those of the air conditioning apparatusand the cross flow fan of FIG. 1 to FIG. 5 discussed above in the firstembodiment, therefore the same reference numerals as those of theembodiment are assigned to the elements and the description will beomitted.

With referring to the partial cross-sectional view of the impeller 2 ofFIG. 49, the impeller 2 including the rings 2 c for supporting theplurality of vanes 2 b is formed in most part by resin materials. Thevane's peripheral end portion A2 is formed by an elastic body 19 such asrubber, for example.

Thus, the vane's peripheral end portion A2 of the vane 2 b facing theperipheral surface of the impeller of the cross flow fan is formed bythe elastic body. For that reason, there is no fear of cutting the tipof one's finger or damaging fingernails in case of touching by mistakethe impeller 2 of the cross flow fan while rotating, when one puts one'shand into the cross flow fan towards the impeller 2 through the airoutlet 14 of the air conditioning apparatus.

Furthermore, in the case of cleaning the impeller, because the vane'speripheral end portion is made of the elastic body, one's finger cannotbe cut while cleaning with such as soft paper. Therefore, a safe airconditioning apparatus may be obtained without losing the ventilatingperformance.

Furthermore, the pressure fluctuation that is received at the peripheralend portion A2 of the vane 2 b by the impeller 2 while rotating may bereduced, so that the noise may be lowered.

Industrial Applicability

As discussed above, according to the present invention, as long as theratio H/φD2 of the height H of the air conditioning apparatus to theouter diameter φD2 of the impeller of the cross flow fan is 2.2 or aboveand 3.0 or below, then the size of the main body of the air conditioningapparatus is not increased and the speed of air flow on the vane'ssurface is reduced at the same flow rate. As a result, the noise becomeslow, and the singular noise is not generated. Moreover, the pressure ofthe impeller can be raised, therefore if a resistance is added on theair inlet side, the drop rate of air flow at the same fan rotationfrequency is reduced, and the flow of blowing air at the air outletbecomes stable. Hence, there is no fear of dew condensed at the airoutlet when cooling. If such as dust accumulates on the filter, there isnot much aggravation caused in the characteristic.

Hence, a highly reliable and silent air conditioning apparatus whichproduces a favorable atmosphere to the ear may be obtained.

According to the next invention, the exit angle β2 of the vane of theimpeller of the cross flow fan is between 23 degrees and 30 degrees.Therefore, the distance between vanes is expanded. When the flow of airpasses through the vanes, because the ventilating resistance is small,the flow of air is not detached at the vane's peripheral end portion.Accordingly, the power consumption of the fan motor for operating theimpeller may be reduced. Hence, an energy-saving air conditioningapparatus having low motor power consumption may be obtained.

According to the next invention, the maximum thickness tm near thecenter of the vane of the impeller of the cross flow fan to thethickness ratio of the thickness of the vane's peripheral end portiont2, which is the minimum thickness and the diameter of the circular-arcshaped vane's peripheral end portion is 1.5 or above and 3.5 or below.This prevents the flow of suction air from detaching on the vane'ssuction surface. Moreover, the speed of air flow between vanes becomesflat, therefore no singular noise is generated. Furthermore, even ifsuch as dust is accumulated on the filter, thereby increasing theventilation resistance of suction air, the noise is not aggregated. As aresult, if such as dust is accumulated on the filter, thereby increasingthe ventilation resistance, no singular noise is generated, and thenoise is not aggregated. Hence, an air conditioning apparatus whichprovides a favorable atmosphere to the ear may be obtained.

According to the next invention, the thickness of the vane's peripheralend portion of the impeller of the cross flow fan is between 0.2 mm and0.5 mm. By thus making it thinner than the thickness of the conventionalcase, the stagnation of the suction flow of air at the tip of the vane'speripheral end portion is reduced and the loss is reduced. Consequently,the power consumption of the fan motor may be reduced. Moreover, even ifminute dust is left unremoved through the filter and accumulated on thevane's peripheral end portion after operating the air conditioningapparatus for a long time, the air flow drop rate during the sameoperating time becomes small compared to the conventional case. For thatreason, the problem that it does not become warm enough when heating andit does not become cool enough when cooling may be solved. Hence, anenergy-saving and highly reliable air conditioning apparatus may beobtained.

According to the next invention, the vane is excised along the circlewhich passes through the circular-arc shaped tip of the vane'speripheral end portion of the vane 2 b of the impeller of the cross flowfan and has the center of the rotating shaft of the impeller as itscenter, so that the vane's peripheral end portion is formed into theshape of a sharp edge. As a result, the stagnation of the flow of air atthe tip of the vane's peripheral end portion is further reduced and theloss is further reduced. For that reason, the consumption power of thefan motor is reduced. Hence, a further energy-saving air conditioningapparatus may be obtained.

According to the next invention, the vane's fitting spaces between vanesof the impeller of the cross flow fan are irregular in pitch. Therefore,in case of the singular noise being generated in a regular pitch, if thevanes are irregularly fitted in pitch, the speed of air flow and thestate of a detaching vortex on the vane's surface differ from oneanother. For that reason, the singular noise is dispersed and the levelof the singular noise is reduced. Furthermore, if the trailing vortex ofthe pipes is sucked into the impeller when the impeller and the heatexchanger come near to each other, the instantaneous lift fluctuation atthe vane's peripheral end portion is dispersed. Consequently, the peaklevel of the rotation noise becomes low. Moreover, this prevents therotation noise from being generated, therefore the gap between theimpeller and the stabilizer as well as the gap between the impeller andthe guide wall are allowed to become narrower. As a result, the staticair pressure of the impeller may be raised and the power consumption ofthe fan motor may be reduced at the same flow rate.

As a result, the singular noise and the rotation noise may be reduced.Hence, an energy-saving and silent air conditioning apparatus whichprovides a favorable atmosphere to the ear may be obtained.

According to the next invention, the stabilizer is formed in such amanner as to locate at the place where the acute angle θ1 formed by thehorizontal line and the straight line is between 30 degrees and 70degrees in the opposite direction to the rotation of the impeller, wherethe straight line connects the closest point of the stabilizer to theimpeller of the cross flow fan and the center of the rotating shaft ofthe impeller, and the horizontal line passes through the center of therotating shaft of the impeller. This restricts the generation of thesingular noise. Thus, the suction area is guaranteed, and the blowingrate of the impeller may be reduced. As a result, the noise becomes low.Hence, a low-noise air conditioning apparatus which provides a favorableatmosphere to the ear may be obtained.

According to the next invention, the stabilizer is formed in such amanner that the acute angle θ2 formed by the two straight lines isbetween 15 degrees and 40 degrees, where one of the straight linesconnects the center of the rotating shaft of the impeller of the crossflow fan and the closest point of the stabilizer to the impeller of thecross flow fan and the other straight line connects the center of therotating shaft of the impeller of the cross flow fan and the lower endof the stabilizer. Thus, the movement of the circulating vortex beinggenerated inside the impeller may be kept stable even if the ventilatingresistance on the air inlet side is increased due to such as dustaccumulated on the filter. For that reason, dew is not condensed in thevicinity of the air outlet 14 when cooling. Furthermore, the area on theair outlet side of the impeller is guaranteed, therefore the noisebecomes low and the input of the fan motor may be reduced. Hence, anenergy-saving, low-noise, and highly reliable air conditioning apparatusmay be obtained.

According to the next invention, the closest point of the guide wall tothe center of the rotating shaft of the impeller of the cross flow fanis disposed at an upper rear portion of the air conditioning apparatus.Furthermore, the guide wall is formed in such a manner that the acuteangle θ3 formed by the straight line connecting the closest point of theguide wall to the impeller and the center of the rotating shaft of theimpeller and the horizontal line passing through the center of therotating shaft of the impeller is between 35 degrees to 80 degrees. Forthat reason, the area on the air inlet side of the cross flow fan isguaranteed, the noise is not aggravated, and the power consumption isreduced. Moreover, in the area on the air outlet side, because the guidewall is extended long, the flow of blown-off air from the impeller canrecover the static air pressure sufficiently enough, and the movement ofblowing air flow becomes stable. As a result, if the ventilatingresistance is increased on the suction side due to such as dust beingaccumulated on the filter, there is no problem when cooling that airflows backward at the air outlet which causes the condensation of dew.Hence, a silent and highly reliable air conditioning apparatus with lownoise may be obtained.

According to the next invention, the vane 2 b is excised along thecircle sharing the center with the center of the impeller 2 and havingthe 2% reduced diameter φD21 from the diameter φD2 of the peripheralcircle of the ring 2 c which is also the outer diameter of the impeller.The remaining internal circumferential portion of the impeller is thevane 2 ba. Vertexes A22 and A23 and an arc A223 are obtained as a resultof the vane 2 b being excised. Furthermore, the straight line connectingthe rotating center O of the impeller and the vertex A22 is O-A22, andthe straight line connecting the rotating center O of the impeller andthe vertex A23 is O-A23. Still further, straight lines obtained byinclining the vertexes A22 and A23 by the fixed same angle θ on the sideof the direction of rotation are U2 and U3, respectively. In thissituation, the vane 2 b is formed by the vane 2 ba and the portion 2 bbin a similar shape to a parallelogram. The portion 2 bb in the similarshape to a parallelogram is enclosed by the two straight lines U2 andU3, the arc A223, and the circle having the diameter φD22 which is atleast smaller than the outside diameter φD2 of the impeller and largerthan the diameter φD21 mentioned above. Furthermore, the vane 2 b isformed with the fixed angle θ being formed at least in such a manner asto be smaller than the angle θ4 formed by the tangent U4 at the vertexA22 and the straight line O-A22. Accordingly, the suction flow of air isa little detached at the segment U3 portion of the vane 2 b′ placed infront of the vane 2 b in the direction of rotation. However, thepressure is provided to the suction surface P3 of the previous vane 2 b′by the segment U2 portion of the vane 2 b. Therefore, the main stream ofthe suction flow of air moves toward the center portion of the passageof air between the vane 2 b and the previous vane 2 b′. As a result,there is no air flow at a high rate and there is no detaching vortex inthe vicinity of the vane's surfaces P2 and P3. Hence, if a highresistance such as a high collection dust removing filer is disposed onthe air inlet side of the air conditioning apparatus, the singular noiseis not generated in a low frequency range and the noise level becomeslow.

In other words, a silent air conditioning apparatus may be obtained.

According to the next invention, the portion facing the periphery of theimpeller 2 of the vane 2 b is not formed in the shape of an edge butformed into the fixed shape of R. Therefore, cleaning is allowed to bedone for the impeller without tearing a cloth or cutting a finger whilecleaning with soft paper (such as waste).

In other words, there is no fear of injury while cleaning. Hence, a safeand highly reliable air conditioning apparatus may be obtained.

According to the next invention, the plurality of vanes 2 b incorporatedinto a single unit supported by the ring 2 c of the impeller 2 of thecross flow fan is inclined by the fixed angle θ1 to the center line O1of the rotating shaft of the fan. Thus, when the vane 2 b passes throughthe area in the vicinity of the stabilizer 3 a, the timing of each vane2 b of each impeller unit 2 a passing through the stabilizer 3 a differsfrom one another in the direction of the length. Accordingly, thegeneration timing of the pressure fluctuation at the peripheral endportion A2 of the vane 2 b differs from one another. As a result, thepressure fluctuation level is lowered and the rotation noise is reduced.Therefore, even if the detaching vortex G1 occurs, because the timing ofgenerating the detaching vortex G1 is different from one another in thedirection of the length, the pressure fluctuation caused by thedetaching vortex G1 is dispersed, so that the noise level Sw of thesingular noise Sm may be lowered.

In other words, a further silent and high-quality air conditioningapparatus which provides a favorable atmosphere to the ear may beobtained.

According to the next invention, in the cross-sectional shape which isenlarged the area in the vicinity of the peripheral end portion A2 ofthe vane 2 b, the impeller 2 including the rings 2 c for supporting theplurality of vanes 2 b is formed in most part by resin materials. Thevane's peripheral end portion A2 is formed by the elastic body 19 suchas rubber, for example. For that reason, there is no fear of cutting thetip of one's finger or damaging fingernails in case of touching bymistake the impeller 2 of the cross flow fan while rotating, when oneputs one's hand into the cross flow fan towards the impeller 2 throughthe air outlet 14 of the air conditioning apparatus.

Furthermore, in the case of cleaning the impeller, because the vane'speripheral end portion is made of the elastic body, one's finger cannotbe cut while cleaning with such as soft paper. Hence, a safe airconditioning apparatus may be obtained without losing the ventilatingperformance.

Moreover, the pressure fluctuation at the peripheral end portion A2 ofthe vane 2 b that is received by the impeller 2 while rotating may bereduced, so that the noise may be lowered.

What is claimed is:
 1. An air conditioning apparatus having a cross flowfan and a heat exchanger, the cross flow fan being provided with animpeller formed by a plurality of vanes and a ring for supporting theplurality of vanes, the cross flow fan being formed by a nozzle portionformed by a stabilizer and an outlet, and a guide wall, wherein a ratioH/φD2 of an outside diameter φD2 of the impeller to a height H of a mainbody of the air conditioning apparatus is 2.2 or above and 3.0 or below.2. The air conditioning apparatus of claim 1, wherein the impeller ofthe cross flow fan includes a vane's exit angle β2 which is between 23degrees and 30 degrees.
 3. The air conditioning apparatus of claim 2,wherein a ratio tm/t2 of a maximum thickness tm of the vane of theimpeller of the cross flow fan to a minimum thickness t2 of the vane isat least 1.5 or above and 3.5 or below so as to reduce singular noisegenerated in a frequency range lower than that of rotation noise, theminimum thickness t2 being a diameter of a peripheral end portion of thevane in a shape of a circular arc, and wherein a thickness of the vaneis gradually varied.
 4. The air conditioning apparatus of claim 1,wherein a ratio tm/t2 of a maximum thickness tm of the vane of theimpeller of the cross flow fan to a minimum thickness t2 of the vane isat least 1.5 or above and 3.5 or below so as to reduce singular noisegenerated in a frequency range lower than that of rotation noise, theminimum thickness t2 being a diameter of a peripheral end portion of thevane in a shape of a circular arc, and wherein a thickness of the vaneis gradually varied.
 5. The air conditioning apparatus of claim 3,wherein the maximum thickness of the vane of the impeller of the crossflow fan is between 0.9 mm and 1.5 mm, and wherein the minimum thicknesst2 of the vane of the impeller of the cross flow fan is between 0.2 mmand 0.6 mm, the minimum thickness t2 being the diameter of theperipheral end portion of the vane in the shape of the circular arc. 6.The air conditioning apparatus of claim 4, wherein the vane of theimpeller of the cross flow fan is formed into a shape of an edgeobtained by cutting the vane along a circle passing through theperipheral end portion of the vane when a center of the circle is acenter O of a rotating shaft of the impeller.
 7. The air conditioningapparatus of claim 4, wherein the plurality of vanes of the impeller ofthe cross flow fan is fitted with an irregular space between the vanesin pitch.
 8. The air conditioning apparatus of claim 1, wherein amaximum thickness of a vane of the impeller of the cross flow fan isbetween 0.9 mm and 1.5 mm, and wherein a minimum thickness t2 of thevane of the impeller of the cross flow fan is between 0.2 mm and 0.6 mm,the minimum thickness t2 of the vane being a diameter of a peripheralend portion of the vane in a shape of a circular arc.
 9. The airconditioning apparatus of claim 1, wherein the vane of the impeller ofthe cross flow fan is formed into a shape of an edge obtained by cuttingthe vane along a circle passing through a peripheral end portion of thevane when a center of the circle is a center O of a rotating shaft ofthe impeller.
 10. The air conditioning apparatus of claim 1, wherein theplurality of vanes of the impeller of the cross flow fan is fitted withan irregular space between the vanes in pitch.
 11. The air conditioningapparatus of claim 1, wherein the stabilizer is formed at a lower frontportion of the air conditioning apparatus in such a manner that an acuteangle formed by a straight line, which connects a closest point of thestabilizer to the impeller of the cross flow fan to a center O of arotating shaft of the impeller, and a horizontal line, which passesthrough the center O of the rotating shaft of the impeller, is between30 degrees and 70 degrees.
 12. The air conditioning apparatus of claim1, wherein the stabilizer is formed in such a manner that an acute angleformed by two straight lines, which connect a center O of the impellerof the cross flow fan, respectively, to a closest point of thestabilizer to the impeller of the cross flow fan and to a lower portionof the stabilizer, is between 15 degrees and 40 degrees.
 13. The airconditioning apparatus of claim 1, wherein the guide wall is formed atan upper rear portion of the air conditioning apparatus in such a mannerthat an angle θ3 formed by a straight line connecting a closest point ofthe guide wall to the impeller of the cross flow fan and a center of arotating shaft of the impeller and a horizontal line passing through thecenter O of the rotating shaft of the impeller, is between 35 degreesand 80 degrees.
 14. The air conditioning apparatus of claim 1, whereinin a cross-sectional view at right angles to a line of a rotating shaftof the impeller of the cross flow fan, a shape of a peripheral endportion of the vane extends to a peripheral side of the impeller in ashape of an inclining parallelogram forward in a direction of rotationof the impeller, but the shape is not projecting outside a periphery ofthe ring for supporting the plurality of vanes.
 15. The air conditioningapparatus of claim 1, wherein two vertexes of a peripheral end portionof the vane facing a peripheral side of the impeller are formed in afixed shape of R when the vertexes extend to the peripheral side of theimpeller in a shape of parallelogram.
 16. The air conditioning apparatusof claim 1, wherein each of the plurality of vanes of the impeller ofthe cross flow fan is inclined by a fixed angle to a rotating shaft ofthe cross flow fan.
 17. The air conditioning apparatus of claim 1,wherein a peripheral end portion of the vane of the impeller of thecross flow fan is formed by an elastic body.